This application relates generally to climate control (heating, ventilating and air-conditioning, or HVAC) systems. More particularly, this application relates to HVAC systems used for motor vehicles.
Primary HVAC systems are often included for climate control of motor vehicles. These systems heat and/or cool air circulated in the occupant cabin of the vehicle. Some of these systems require energy from the vehicle engine such that the vehicle engine must be running (i.e. idling) for the HVAC system to be fully functional when the vehicle is parked. This is particularly an issue with vehicles that are commonly occupied while parked, such as recreational vehicles (RVs), busses, commercial trucks with sleeper cabs, and other such vehicles. However, idling a vehicle engine for a period of time to operate the HVAC system consumes relatively large quantities of fuel and generates exhaust.
The need for climate control in a vehicle when the engine is off is particularly needed in over the road commercial trucks. Drivers of these vehicles often take breaks in their vehicles and, when equipped with a sleeping cabin, may occupy the vehicle over night. Maintaining a comfortable temperature in the cabin at these times when the engine is turned off may require an auxiliary HVAC system.
To avoid unnecessary fuel consumption and limit the generation of exhaust while still providing a comfortable cabin temperature, auxiliary HVAC units that are independent of the vehicle engine have been used. These systems may include multiple subassemblies requiring complex installation. Also, many such systems include only a portion of a refrigerant loop. Such systems must be connected to the vehicle's primary refrigerant loop when installed. This then requires charging the system with refrigerant when installed in the vehicle. This complicates aftermarket installation of the systems.
Accordingly, there is a need for an integrated auxiliary HVAC system that does not require connection to the vehicle's primary refrigerant loop. There is also a need for a compact auxiliary HVAC system that can be easily installed into a vehicle as a single unit.